The present invention has particular applicability to vacuum-type circuit-interrupters which are utilized in metal-clad switchgear constructions, such as set forth in the following U.S. Pat. Nos.: 3,590,188-Frink et al; 3,531,608-Bateman; 3,435,162-Kozlovic, and 3,603,753-Frink.
It is desirable to provide the higher-amperage circuit-interrupters, say, for example, 3,000 amperes, with improved cost-reduction features, without jeopardizing reliability and capability, and to utilize in connection therewith low-cost component parts.
The present invention has particular applicability to roll-in-type switchgear units, which roll into cell structures, such as set forth in FIGS. 35 and 37 in U.S. Pat. No. 3,590,188, and FIGS. 4-6 of the aforesaid U.S. Pat. No. 3,603,753-Frink, and it is, consequently, desirable to provide a proper and accurate alignment means between the movable primary disconnecting contacts, associated with the roll-in-type switchgear unit, and the relatively stationary primary disconnecting contacts, the latter being associated and mounted interiorly within the cooperating metal-clad cell structure.
In the past, mechanical support and alignment of primary conductors were achieved by babbiting or casting the conductors into a large porcelain structure, such as shown in U.S. Pat. No. 3,437,554, issued Apr. 8, 1969 to James Gamble. This resulted in shielding of the power conductor from the air and thereby limiting the current rating to 2,000 amperes in one particular rating circuit-breaker.